WO2013180162A1

WO2013180162A1 - Thermoplastic resin foam and foam-based sealing material

Info

Publication number: WO2013180162A1
Application number: PCT/JP2013/064872
Authority: WO
Inventors: 充宏金田; 齋藤　誠; 逸大畑中; 和通加藤; 清明児玉; 廣諭安田
Original assignee: 日東電工株式会社
Priority date: 2012-05-31
Filing date: 2013-05-29
Publication date: 2013-12-05
Also published as: CN104364303A; KR20150027031A; KR102174106B1; JP2014005452A; JP6039505B2

Abstract

One of the purposes of the present invention is to provide a resin foam having excellent processability by imparting remarkable shear fracture anisotropy in a specific direction with the flexibility kept. The other of the purposes thereof is to provide a foam-based sealing material. The present invention pertains to a resin foam which comprises a thermoplastic resin, said resin foam being characterized in that: the maximum breaking strength (Smax) of the foam is 0.1 to 3MPa; and the Smax/Smin ratio thereof is 1.5 to 6 [wherein Smin is the breaking strength of the foam in the direction perpendicular to the direction in which the maximum breaking strength is observed]. Further, it is preferable that the breaking elongation (SSmax) of the foam in the direction in which the maximum breaking strength is observed is 200% or less with the SSmax/SSmin ratio being 1.5 to 6 [wherein SSmin is the breaking elongation of the foam in the direction perpendicular to the direction in which the maximum breaking strength is observed].

Description

Thermoplastic resin foam and foam sealing material

The present invention relates to a thermoplastic resin foam and a foam sealing material.

Conventionally, resin foam has been used as a gasket material for mobile phones and portable information terminals, or as a packing sheet or tape, a sealing tape, a protective sheet, or a tape.
Examples of the resin foam include a low-foam urethane resin foam of fine cells having an open-cell structure, a compression-molded high-foam urethane, and a polyethylene resin foam having closed cells and an expansion ratio of about 30 times, density A polyolefin-based resin foam (see Patent Documents 1 and 2) having a weight of 0.2 g / cm ³ or less has been proposed. And it is manufactured in the form of a sheet or tape by stretching or extruding a resin whose surface shape is controlled.

Such a resin foam is usually applied by being processed into a predetermined shape and fixed at a predetermined site. However, since the resin foam is flexible and easily broken, it can be used during processing or fixing. In some cases, breakage occurred unintentionally. Alternatively, a large load is applied to the cutting or shearing in a predetermined direction, and at the time of the cutting or shearing, it extends in an unintended direction and the blade breaks, or it becomes difficult to form a trigger for the breakage due to the extension, and the hand cutting property is reduced. In some cases, it was not completely satisfactory with respect to the hand cutting property during processing.

JP 2005-227392 A JP 2007-291337 A

It is an object of the present invention to provide a resin foam and a foam sealing material that can impart excellent anisotropy to shear fracture in a specific direction while maintaining flexibility, and can realize good processability. .

The present invention includes the following inventions.
(1) A resin foam containing a thermoplastic resin,
The foam has a maximum breaking strength Smax of 0.1 MPa to 3 MPa, and a ratio Smax / Smin between the maximum breaking strength Smax and a breaking strength Smin in a direction perpendicular to the direction showing the maximum breaking strength is 1.5 to 6 The resin foam characterized by being.
(2) The elongation at break SSmax in the direction showing the maximum breaking strength is 200% or less,
The resin foam according to (1), wherein a breaking elongation ratio SSmax / SSmin between a breaking elongation SSmax in the direction showing the maximum breaking strength and a breaking elongation SSmin in a direction perpendicular to the direction showing the maximum breaking strength is 1.5 to 6. body.
(3) The ratio Cmax / Cmin between the bubble size Cmax in the direction showing the maximum breaking strength and the bubble size Cmin in the direction orthogonal to the direction showing the maximum breaking strength is 1.2 to 5 (1) or (2 ) The resin foam described.
(4) The resin foam according to any one of (1) to (3), which has an apparent density of 0.01 to 0.2 g / cm ³ .
(5) The resin foam according to any one of (1) to (4), which is obtained by decompression treatment of a thermoplastic resin composition impregnated with a high-pressure gas.
(6) The resin foam according to (5), wherein the gas is an inert gas.
(7) The resin foam according to (6), wherein the inert gas is carbon dioxide or nitrogen.
(8) The resin foam according to any one of (5) to (7), wherein the gas is a gas in a supercritical state.
(9) A foamed sealing material comprising the resin foam according to any one of (1) to (8) above.
(10) The foamed sealing material according to (9), comprising an adhesive layer disposed on one or both surfaces of the foam.
(11) The foamed sealing material according to (10), wherein the adhesive layer is disposed on the surface of the resin foam via a film layer.

According to the present invention, it is possible to provide a resin foam and a foam sealing material capable of realizing good processability by imparting significant anisotropy to shear fracture in a specific direction while maintaining flexibility. Can do.

It is a top view of the sample for enforcing the evaluation method of the hand cutting property of the resin foam of this invention. It is the schematic which shows the evaluation aspect of the sample in the evaluation method of the hand cutting property of the resin foam of this invention. It is the schematic of the principal part in the manufacturing process for demonstrating the extending | stretching method of the resin foam of this invention.

The resin foam of the present invention is a foam containing a thermoplastic resin, and can be obtained by foaming or molding a thermoplastic resin composition. The shape of the resin foam of this invention is not specifically limited, For example, any forms, such as a lump shape, a sheet form, and a film form, may be sufficient.

[Physical properties of resin foam]
The resin foam of the present invention has a maximum breaking strength Smax of 0.1 MPa to 3 MPa, preferably 0.1 MPa to 2 MPa, more preferably 0.2 MPa to 2 MPa, and further preferably 0.3 MPa to 2 MPa.
Here, the maximum breaking strength Smax means the largest breaking strength among the breaking strengths in various directions of the resin foam.
In order to obtain such a breaking strength, first, the breaking strength in an arbitrary direction (for example, direction A) of the resin foam is measured, and further, a center X is set on the axis in the direction A, and this center The shaft is rotated by 10 ° with respect to X, and the breaking strength in each direction indicated by the shaft is measured (18 directions in total). Among them, the rupture strength in the direction with the largest rupture strength (hereinafter sometimes referred to as “maximum rupture strength direction”) is selected, and this is set as the maximum rupture strength Smax.
By having such a maximum breaking strength, a resin foam having an appropriate strength can be obtained.
In the resin foam of the present invention, the direction showing the maximum breaking strength is usually the MD direction (flow direction).

In the resin foam of the present invention, the ratio Smax / Smin between the maximum breaking strength Smax described above and the breaking strength Smin in the direction perpendicular to the maximum breaking strength direction is 1.5 to 6, preferably 1.8. -6, more preferably 2-6, still more preferably 2-5.
By having such a breaking strength ratio, since the anisotropy can be remarkably improved in the shear fracture in a specific direction, it is possible to realize good workability, particularly hand cutting. Therefore, the resin foam of the present invention can be used as an easy-open tape that requires anisotropy, a sheet excellent in on-site workability, and the like.

The resin foam of the present invention further has a breaking elongation SSmax in the maximum breaking strength direction of preferably 200% or less, more preferably 180% or less, and even more preferably 160% or less. Moreover, Preferably it is 100% or more, More preferably, it is 105% or more.
By having such elongation at break, elongation at the time of processing or fixing can be prevented. In addition, it is possible to effectively prevent breakage due to elongation of the tape when used as a tape. The elongation of the resin foam can be evaluated as extensibility, which is an elongation rate when a predetermined load is applied. For example, if the extensibility at a load of 0.5 N is 5.0% or less, it is difficult to elongate and it can be determined that it is good. If the extensibility at a load of 1.0 N is 10.0% or less, it is difficult to elongate, and it can be judged as good. The spreadability can be measured by the method described in Examples described later.

The resin foam of the present invention further has a breaking elongation ratio SSmax / SSmin between the breaking elongation SSmax in the maximum breaking strength direction and the breaking elongation SSmin in the direction perpendicular to the maximum breaking strength direction, preferably 1.5 to 6, More preferably, it is 2 to 6, and further preferably 2.5 to 6.
By having such a breaking elongation ratio, the elongation in the direction orthogonal to the maximum breaking direction is reduced, so that cutting in a specific direction can be facilitated.

The resin foam of the present invention is, for example, a closed cell structure or a semi-continuous semi-closed cell structure (a cell structure in which a closed cell structure and a semi-continuous semi-closed cell structure are mixed, and the ratio is particularly (It is not limited). In particular, a cell structure in which the closed cell ratio of the resin foam is 50% or less, preferably 40% or less, more preferably 35% or less can be mentioned. With this range, air can easily escape from the resin during compression deformation when an impact is applied, and sufficient shock absorption can be exhibited. Further, there is a cell structure in which the closed cell ratio of the resin foam is 10% or more, preferably 15% or more, more preferably 20% or more. By this range, the passage of fine particles such as dust can be prevented, and the dustproofness can be improved.
The closed cell ratio can be measured, for example, by the method described in the examples.

In the resin foam of the present invention, the ratio Cmax / Cmin between the bubble size Cmax in the maximum breaking strength direction and the bubble size Cmin in the direction perpendicular to the maximum breaking strength direction is preferably 1.2 to 5, more preferably Is from 1.2 to 4, more preferably from 1.2 to 3.5, even more preferably from 1.3 to 3.5.

Here, the bubble size is an average value of 10 bubble diameters measured by the following method.
First, cut in the direction perpendicular to the main surface of the resin foam (thickness direction) with a cutter parallel to the direction of the maximum breaking strength of the resin foam and the direction orthogonal to this direction, creating a smooth cross section To do. Next, these cross sections are observed with a Keyence microscope (for example, trade name “VHX-600” manufactured by Keyence Corporation). Then, 10 points are extracted from those having a large bubble size within the measurement range of 3000 μm × 2500 μm, the area of the bubbles is converted into a diameter, and an average value thereof is obtained to obtain the bubble diameter.

In the resin foam of the present invention, the cell diameter is preferably 50 to 300 μm, more preferably 70 to 300 μm, more preferably 70 μm, in a vertical direction (thickness direction) cut surface parallel to the maximum breaking strength direction. Is from 100 to 300 μm, more preferably from 100 to 250 μm. Further, the bubble diameter in the vertical (thickness direction) cut surface parallel to the direction perpendicular to the maximum breaking strength direction is preferably 10 to 200 μm, more preferably 30 to 200 μm, and further preferably 50 to 200 μm. More preferably 80 to 180 μm.

In the resin foam of the present invention, by setting the cell diameter of the foam within this range, anisotropy in the intended direction can be further realized, and good workability and hand cutting properties are ensured. In addition, the cut surface has less unevenness and can be made a sharp surface.

The resin foam of the present invention further has an apparent density of preferably 0.01 to 0.20 g / cm ³ , more preferably 0.01 to 0.15 g / cm ³ , and still more preferably 0.01 to 0.00. It is 10 g / cm ³ , more preferably 0.02 to 0.08 g / cm ³ . When the apparent density is within this range, sufficient strength can be secured, good workability (particularly punching workability) can be obtained, and at the same time, flexibility can be secured.

The resin foam of the present invention has a tensile modulus of preferably 5.0 to 14.0 MPa, more preferably 5.5 to 13.5 MPa, and still more preferably 6.0 to 13.0 MPa. By setting it as such a range, when the resin foam is pulled, it is possible to effectively prevent the resin foam from extending and breaking in an unintended direction without causing plastic deformation. Thereby, the spreadability is low, and excellent workability can be exhibited.
A tensile elasticity modulus is calculated | required by the tension test based on JISK6767.

[Material of resin foam]
The resin foam of the present invention is formed of a thermoplastic resin or a resin composition containing a thermoplastic resin. Examples of the thermoplastic resin include low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, a copolymer of ethylene and propylene, ethylene or propylene and another α-olefin (for example, butene -1, pentene-1, hexene-1, 4-methylpentene-1, etc.), ethylene and other ethylenically unsaturated monomers (for example, vinyl acetate, acrylic acid, acrylic ester, methacrylic) Polyolefin resins such as copolymers with acid, methacrylic acid ester, vinyl alcohol, etc.); styrene resins such as polystyrene, acrylonitrile-butadiene-styrene copolymer (ABS resin); 6-nylon, 66-nylon, 12 -Polyamide resins such as nylon; polyamideimide Polyurethane; Polyimide; Polyetherimide; Acrylic resin such as polymethyl methacrylate; Polyvinyl chloride; Polyvinyl fluoride; Alkenyl aromatic resin; Polyester resin such as polyethylene terephthalate and polybutylene terephthalate; Polycarbonate such as bisphenol A polycarbonate; Polyacetal; polyphenylene sulfide and the like.
A thermoplastic resin can be used individually or in combination of 2 or more types. When the thermoplastic resin is a copolymer, the copolymer may be a random copolymer or a block copolymer.

As the thermoplastic resin, a polyolefin-based resin is preferable from the viewpoints of characteristics such as mechanical strength, heat resistance, and chemical resistance, and molding surfaces such as easy melt thermoforming.
Preferred examples of the polyolefin resin include a resin having a broad molecular weight distribution and having a shoulder on the high molecular weight side, a micro-crosslinking type resin (a slightly cross-linked type resin), a long-chain branched type resin, and the like.

The thermoplastic resin includes a rubber component and / or a thermoplastic elastomer component.
Since the rubber component and the thermoplastic elastomer component have, for example, a glass transition temperature of room temperature or lower (for example, 20 ° C. or lower), flexibility and shape followability when a resin foam is obtained are extremely good.

The rubber component and the thermoplastic elastomer component are not particularly limited as long as they have rubber elasticity and can be foamed. For example, natural or natural rubber, polyisobutylene, polyisoprene, chloroprene rubber, butyl rubber, nitrile butyl rubber, or the like Synthetic rubbers; Ethylene-propylene copolymers, ethylene-propylene-diene copolymers, ethylene-vinyl acetate copolymers, polybutenes, olefinic elastomers such as chlorinated polyethylene; styrene-butadiene-styrene copolymers, styrene-isoprene -Styrene elastomers such as styrene copolymers and hydrogenated products thereof; polyester elastomers; polyamide elastomers; various thermoplastic elastomers such as polyurethane elastomers.
You may use these individually or in combination of 2 or more types.

Among these, as the rubber component and / or the thermoplastic elastomer component, an olefin elastomer is preferable. The olefin elastomer has good compatibility with the polyolefin resin exemplified as the thermoplastic resin.

The olefin elastomer may be of a type having a structure in which the resin component A (olefin resin component A) and the rubber component B are microphase separated. In addition, a type in which resin component A and rubber component B are physically dispersed, a type in which resin component A and rubber component B are dynamically heat-treated in the presence of a crosslinking agent (dynamic crosslinkable thermoplastic elastomer, TPV).

In particular, as the olefin elastomer, a dynamically crosslinked thermoplastic olefin elastomer (TPV) is preferable.
The dynamically crosslinked thermoplastic olefin elastomer has a higher elastic modulus and a smaller compression set than TPO (non-crosslinked thermoplastic olefin elastomer). Thereby, the recoverability is good, and when the resin foam is used, the excellent recoverability is exhibited.

As described above, the dynamically crosslinked thermoplastic olefin elastomer is a mixture containing the resin component A (olefin resin component A) forming a matrix and the rubber component B forming a domain, in the presence of a crosslinking agent. It is a multiphase polymer having a sea-island structure in which crosslinked rubber particles are finely dispersed as domains (island phases) in the resin component A, which is a matrix (sea phase), obtained by dynamic heat treatment.

Examples of such a dynamically crosslinked thermoplastic olefin elastomer include, for example, JP 2000-007858 A, JP 2006-052277 A, JP 2012-072306 A, JP 2012-056768 A, JP-A-2010-241897, JP-A-2009-0697969, RE-list 03/002654, etc., “Zeotherm” (manufactured by Zeon Corporation), “Thermorun” (manufactured by Mitsubishi Chemical Corporation), “Surlink” 3245D "(manufactured by Toyobo Co., Ltd.) and the like.

In the case where the resin constituting the resin foam of the present invention contains a rubber component and / or a thermoplastic elastomer component together with the thermoplastic resin, the content is not particularly limited. For example, the ratio of the thermoplastic resin to the rubber component and / or the thermoplastic elastomer component in the resin constituting the resin foam of the present invention is preferably 70/30 to 30/70, more preferably on a weight basis. Is 60/40 to 30/70, even more preferably 50/50 to 30/70, even more preferably 60/40 to 10/90, 58/42 to 10/90, 55/45 to 10/90. If the ratio of the rubber component and / or the thermoplastic elastomer component is too small, the cushioning property of the resin foam tends to be lowered or the recoverability after compression may be lowered. On the other hand, the rubber component and / or the thermoplastic elastomer component If the ratio is too large, outgassing tends to occur during foam formation, and it may be difficult to obtain a highly foamable foam.

In the resin foam of the present invention, in order to realize flexibility at high compression and shape recovery after compression, that is, to enable large deformation and prevent plastic deformation, so-called rubber elasticity is used. It is suitable that it is made of an excellent material. From that viewpoint, it is preferable that the resin foam of the present invention includes a rubber component and / or a thermoplastic elastomer component together with the above-described thermoplastic resin as a constituent resin.

Further, the resin foam of the present invention preferably further contains a nucleating agent. When the nucleating agent is contained, the cell diameter can be easily adjusted, and a foam having an appropriate flexibility and excellent cutting processability can be obtained.

Examples of the nucleating agent include oxides and composite oxides such as talc, silica, alumina, zeolite, calcium carbonate, magnesium carbonate, barium sulfate, zinc oxide, titanium oxide, aluminum hydroxide, magnesium hydroxide, mica, and montmorillonite. Metal carbonates, metal sulfates, metal hydroxides; carbon particles, glass fibers, carbon tubes, and the like. In addition, a nucleating agent is used individually or in combination of 2 or more types.

The average particle size of the nucleating agent is not particularly limited, but is preferably 0.3 to 1.5 μm, more preferably 0.4 to 1.2 μm. By setting it as such an average particle diameter, sufficient function as a nucleating agent can be exhibited. In addition, a high expansion ratio can be realized without the nucleating agent breaking through the cell walls.
This average particle diameter can be measured by a laser diffraction particle size distribution measuring method. For example, it can be measured (AUTO measurement) from a dispersion dilution of a sample by “MICROTRAC MT-3000” manufactured by LEEDS & NORTHRUP INSTRUMENTS.

In the resin foam of the present invention, the content when such a nucleating agent is included is not particularly limited, and is preferably 0.5 to 150 parts by weight, more preferably 100 parts by weight of the constituent resin. 2 to 140 parts by weight, still more preferably 3 to 130 parts by weight.

Since the resin foam of this invention is comprised with a thermoplastic resin and is easy to burn, it is preferable to contain a flame retardant.
As the flame retardant, a non-halogen-nonantimony inorganic flame retardant is preferable.
Examples of such inorganic flame retardants include metal hydroxides and hydrates of metal compounds. More specifically, aluminum hydroxide; magnesium hydroxide; hydrates of magnesium oxide and nickel oxide; hydrates of magnesium oxide and zinc oxide, and the like. Among these, magnesium hydroxide is preferable. The hydrated metal compound may be surface-treated. A flame retardant is used individually or in combination of 2 or more types.

In the resin foam of the present invention, the content when a flame retardant is contained is preferably 5 to 70 parts by weight, more preferably 25 to 65 parts by weight, with respect to 100 parts by weight of the constituent resin.

The resin foam of the present invention further has a polar functional group, a melting point of 50 to 150 ° C., and contains at least one aliphatic compound selected from fatty acids, fatty acid amides, and fatty acid metal soaps. Also good. Of these, fatty acids and fatty acid amides are preferred.

When such an aliphatic compound is contained in the resin foam of the present invention, the cell structure is less likely to collapse during processing (particularly punching processing), shape recovery is improved, and workability (particularly, (Punching workability) is further improved. Such an aliphatic compound has high crystallinity, and when added to the thermoplastic resin (especially polyolefin resin), a strong film is formed on the resin surface, and the wall surfaces of the bubbles forming the cell structure block each other. This is presumed to have a function to prevent the above.

Such aliphatic compounds, particularly those containing a highly polar functional group, are difficult to be compatible with polyolefin resins, so that they easily precipitate on the surface of the resin foam and exhibit the above effects. Cheap.

The melting point of the aliphatic compound is preferably 50 to 50 from the viewpoints of lowering the molding temperature when foam-molding the resin composition, suppressing deterioration of the resin (particularly polyolefin resin), imparting sublimation resistance, and the like. 150 ° C., more preferably 70 to 100 ° C.

The fatty acid preferably has about 18 to 38 carbon atoms, more preferably about 18 to 22 carbon atoms. Specific examples include stearic acid, behenic acid, 12-hydroxystearic acid and the like. Of these, behenic acid is particularly preferable.

The fatty acid amide is preferably a fatty acid amide having about 18 to 38 carbon atoms in the fatty acid moiety, more preferably about 18 to 22 carbon atoms, and may be either monoamide or bisamide. Specific examples include stearic acid amide, oleic acid amide, erucic acid amide, methylene bis stearic acid amide, and ethylene bis stearic acid amide. Of these, erucic acid amide is particularly preferable.

Examples of the fatty acid metal soap include aluminum, calcium, magnesium, lithium, barium, zinc and lead salts of the above fatty acids.

In the resin foam of the present invention, the content when such an aliphatic compound is contained is not particularly limited, and is preferably 1 to 5 parts by weight, more preferably 100 parts by weight of the constituent resin. The amount is 1.5 to 3.5 parts by weight, more preferably 2 to 3 parts by weight. Thereby, sufficient pressure can be maintained when the resin is subjected to foam molding, the content of the foaming agent (for example, an inert gas such as carbon dioxide) can be secured, and a high foaming ratio can be obtained.

The resin foam of the present invention may contain a lubricant. Thereby, while improving the fluidity | liquidity of a resin composition, the thermal deterioration of resin can be suppressed. A lubricant is used individually or in combination of 2 or more types.

The lubricant is not particularly limited. For example, hydrocarbon lubricants such as liquid paraffin, paraffin wax, microwax and polyethylene wax; butyl stearate, monoglyceride stearate, pentaerythritol tetrastearate, hydrogenated castor oil, stearyl stearate And ester lubricants. Moreover, content of a lubricant can be suitably selected in the range which does not impair the effect of this invention.

The resin foam of the present invention may contain other additives as necessary. Examples of such additives include anti-shrinkage agents, anti-aging agents, heat stabilizers, light stabilizers such as HALS, weathering agents, metal deactivators, ultraviolet absorbers, light stabilizers, copper damage inhibitors, and the like. Stabilizers, antibacterial agents, fungicides, dispersants, tackifiers, colorants such as carbon black and organic pigments, fillers, and the like. In particular, when a dynamically crosslinked thermoplastic olefin elastomer is used, a composition containing an additive (for example, a colorant such as carbon black, a softener, etc.) may be used. These additives are used alone or in combination of two or more.
The content of these additives can be appropriately selected within a range that does not impair the effects of the present invention.

[Method for producing resin foam]
The resin foam of the present invention is obtained by mixing or kneading a thermoplastic resin (including a rubber component and / or a thermoplastic elastomer component), and optionally an additive such as a nucleating agent, an aliphatic compound, or a lubricant. Using the obtained resin composition, it can be produced by foaming or molding the resin composition. In particular, the anisotropic structure of bubbles can be formed by stretching.

The foaming method used when foaming or molding the resin composition is not particularly limited, and examples thereof include commonly used methods such as a physical method and a chemical method. A general physical method is a method of forming bubbles by dispersing a low boiling point liquid (foaming agent) such as chlorofluorocarbons or hydrocarbons in a resin, and then heating to volatilize the foaming agent. Moreover, a general chemical method is a method in which bubbles are formed by a gas generated by thermal decomposition of a compound (foaming agent) added to a resin.

In the present invention, as a foaming method, a method using a high-pressure gas as a foaming agent is preferable because a foam having a small cell diameter and a high cell density can be easily obtained. In particular, a method using a high-pressure inert gas as a foaming agent is preferable.
As a method of using a high-pressure gas as a foaming agent, a method in which a resin composition is impregnated with a high-pressure gas and then subjected to a pressure reducing step is preferable. Specifically, an unfoamed molded article made of a resin composition And a method of forming through a step of depressurizing after impregnating with a high-pressure gas, a method of forming a molten resin composition by impregnating the gas under a pressurized condition, and then subjecting it to molding with reduced pressure. It is done.

The inert gas is not particularly limited as long as it is inert and can be impregnated into the resin that is the material of the resin foam, and examples thereof include carbon dioxide, nitrogen, and air. These gases may be mixed and used. Of these, carbon dioxide or nitrogen is preferred because the amount of impregnation into the resin is large and the impregnation rate is high.

Furthermore, from the viewpoint of increasing the impregnation rate into the resin composition, the high-pressure gas (particularly inert gas, and further carbon dioxide) is preferably a gas in a supercritical state. In the supercritical state, the solubility of the gas in the resin is increased and high concentration can be mixed. In addition, when the pressure drops suddenly after impregnation, since it is possible to impregnate at a high concentration as described above, the generation of bubble nuclei increases, and the density of bubbles formed by the growth of the bubble nuclei has a porosity. Even if they are the same, they become larger, so that fine bubbles can be obtained. For example, carbon dioxide has a critical temperature of 31 ° C. and a critical pressure of 7.4 MPa.

As a method of foaming or molding a resin composition by a method using a high-pressure gas as a foaming agent, an unfoamed resin molded body (unfoamed resin molded article) is obtained by molding a resin composition into an appropriate shape such as a sheet shape in advance. And a non-foamed resin molded article is impregnated with a high-pressure gas and foamed by releasing the pressure. Moreover, the continuous method which knead | mixes a resin composition with a high pressure gas under pressure, shape | molds it simultaneously, releases pressure, and performs shaping | molding and foaming simultaneously is mentioned.

As a method of forming an unfoamed resin molded body to be used for foaming when foaming or molding a resin composition by a batch method, for example, the resin composition is an extruder such as a single screw extruder or a twin screw extruder. Molding method using a kneading machine equipped with blades such as rollers, cams, kneaders, Banbury molds, etc., and then kneading the resin composition to a predetermined thickness using a hot plate press or the like And a method of molding the resin composition using an injection molding machine. In addition, the unfoamed resin molded body can be formed by other molding methods besides extrusion molding, press molding, and injection molding. Furthermore, the shape of the unfoamed resin molded body is not particularly limited, and various shapes can be selected depending on the application, and examples thereof include a sheet shape, a roll shape, a plate shape, and a lump shape.
Thus, when foaming or molding the resin composition in a batch mode, the resin composition can be molded by an appropriate method that can obtain an unfoamed resin molded body having a desired shape and thickness.

When foaming or molding a resin composition by a batch method, the obtained unfoamed resin molded product is placed in a pressure vessel (high pressure vessel) and injected with high pressure gas (especially inert gas or even carbon dioxide) ( Gas) impregnating a non-foamed resin molded body with a high-pressure gas, releasing the pressure when the sufficiently high-pressure gas is impregnated (usually up to atmospheric pressure), and creating bubble nuclei in the resin Bubbles are formed in the resin through a decompression step to be generated, and in some cases (if necessary), a heating step in which bubble nuclei are grown by heating. Bubble nuclei may be grown at room temperature without providing a heating step.

As the foaming or molding of the resin composition in a continuous system, the resin composition is kneaded using an extruder such as a single screw extruder or a twin screw extruder while a high pressure gas (especially an inert gas, Is injected (introduced) carbon dioxide), and the pressure is released by extruding the resin composition through a kneading impregnation step for impregnating the resin composition with a sufficiently high pressure gas, a die provided at the tip of the extruder ( Usually, up to atmospheric pressure), foaming or molding may be performed by a molding decompression step in which molding and foaming are performed simultaneously. In the kneading impregnation step and the molding pressure reduction step, an injection molding machine or the like can be used in addition to the extruder. In addition, when foaming or molding the resin composition in a continuous manner, a heating step for growing bubbles by heating may be provided as necessary.

In either the batch method or the continuous method, after the bubbles are grown, if necessary, the shape may be fixed rapidly by cooling with cold water or the like. The introduction of high-pressure gas may be performed continuously or discontinuously. As a heating method for growing bubble nuclei, known methods such as a water bath, an oil bath, a hot roll, a hot air oven, a far infrared ray, a near infrared ray, and a microwave can be employed.

Moreover, when manufacturing the resin foam of this invention, in either a batch system or a continuous system, after passing through the process mentioned above or extending | stretching in the process mentioned above, anisotropy is provided to a resin foam. It is necessary.

Specifically, it is preferable to stretch by the following method.
For example, as shown in FIG. 3A, when the resin is extruded into a sheet form from a slit-shaped T die or slit die 10, the nip roll 12 is melted or semi-molten before the resin cools and solidifies. As shown in FIG. 3B, when the resin is extruded from the slit-shaped T die or the slit die 10 into a sheet shape, the resin sheet 11 is held on the roll 13 before the resin cools and solidifies. 3C, as shown in FIG. 3C, a method of holding the resin sheet 11 a plurality of times so that the resin sheet 11 does not slip; and as shown in FIG. 3D, between the rolls 13 so that the resin sheet 11 does not slip. Method of niping and pulling; as shown in FIG. 3E, the resin sheet 11 is sandwiched between the endless belts 14, brought into contact with both sides, and slid by friction. The method taken off manner not; as shown in FIG. 3F, a method of taking up to prevent slipping by friction between the belt and the resin sheet 11 in contact on the endless belt 14 and the like. Further, as shown in FIG. 3G, the resin sheet 11 is extruded from the cylindrical die 20 into a ring shape, and one portion of the ring shape is cut with a cutter or the like and developed into a sheet shape. It may be a method of sandwiching and taking out.

When the above-described method is carried out, if the speed at which the resin sheet is fed by a roll or a belt is defined as the molding speed, the ratio of the resin extrusion speed and the molding speed is 1: The ratio is preferably 1.2 to 1: 5. By setting it as this range, the resin sheet is not crushed in the thickness direction, and the bubble shape can be appropriately elongated, and the porosity, cushioning properties and flexibility can be ensured.
The molding speed is not particularly limited, and is preferably in the range of 2 m / min to 100 m / min in consideration of the ability to stably mold the resin sheet and production efficiency.

In addition, when the resin sheet is nipped by a roll or a belt, it is preferable to nip by applying pressure so that the formed foam is not crushed in the thickness direction.

The mixing amount of the gas at the time of foaming or molding the resin composition is not particularly limited. For example, it is preferably 2 to 10% by weight, more preferably 2.5 to 2.5%, based on the total amount of the resin components in the resin composition. 8% by weight, still more preferably 3-6% by weight. By setting it as this range, a foam with a high foaming rate can be obtained, without gas separating in a molding machine.

The pressure when impregnating the unfoamed resin molded product or resin composition with the gas impregnation step in the batch method or the kneading impregnation step in the continuous method when foaming or molding the resin composition depends on the type of gas and the operability. For example, when an inert gas, particularly carbon dioxide, is used as the gas, it is preferably 6 MPa or more (for example, 6 to 100 MPa), more preferably 8 MPa or more (for example, 8 to 8). 100 MPa). By setting such a pressure, it is possible to moderately control the bubble growth during foaming, to reduce the cell diameter, and to provide a good dustproof effect. This is because the amount of gas impregnation becomes an appropriate amount, and the number of bubble nuclei formed can be adjusted to an appropriate number by controlling the bubble nucleus formation rate. In addition, the cell diameter and the bubble density can be easily controlled.

In the gas impregnation step in the batch method or the kneading impregnation step in the continuous method when foaming or molding the resin composition, the temperature when impregnating the non-foamed resin molded product or resin composition with the high-pressure gas is the gas or resin used. Depending on the type, etc., a wide range can be selected. Considering operability and the like, for example, the temperature is 10 to 350 ° C. In the batch method, the impregnation temperature when impregnating a sheet-like unfoamed resin molded article with high-pressure gas is preferably 10 to 250 ° C, more preferably 40 to 240 ° C, and further preferably 60 to 230 ° C. In the continuous method, the temperature at which the high-pressure gas is injected into the resin composition and kneaded is preferably 60 to 350 ° C., more preferably 100 to 320 ° C., and still more preferably 150 to 300 ° C. When carbon dioxide is used as the high-pressure gas, the temperature during impregnation (impregnation temperature) is preferably 32 ° C. or higher (particularly 40 ° C. or higher) in order to maintain a supercritical state.

The pressure reduction rate in the pressure reduction step when foaming or molding the resin composition in a batch method or a continuous method is not particularly limited, and is preferably 5 to 300 MPa / second in order to obtain uniform fine bubbles. The heating temperature in the heating step is, for example, 40 to 250 ° C. (preferably 60 to 250 ° C.).

When the above method is used when foaming or molding the resin composition, a highly foamed resin foam can be produced, and a thick resin foam can be produced. For example, when the resin composition is foamed or molded in a continuous manner, in order to maintain the pressure inside the extruder in the kneading impregnation step, the gap of the die attached to the tip of the extruder is as narrow as possible (usually 0.1 to 1). About 0 mm). Therefore, in order to obtain a thick resin foam, the resin composition extruded through a narrow gap is foamed at a high magnification. Conventionally, since a high expansion ratio cannot be obtained, the thickness of the formed resin foam is limited to a thin one (for example, 0.5 to 2.0 mm). In contrast, by foaming or molding the resin composition using a high-pressure gas, it is possible to finally obtain a resin foam having a thickness of 0.50 to 5.00 mm continuously.

Depending on the type of gas, thermoplastic resin, rubber component and / or thermoplastic elastomer component, the characteristics, such as apparent density, breaking strength, breaking elongation, bubble size, hand tearability, for example, gas impregnation step Alternatively, operating conditions such as temperature, pressure, and time in the kneading impregnation process, pressure reducing speed in the pressure reducing process or blade forming pressure reducing process, operating conditions such as temperature and pressure, heating temperature in the heating process after pressure reduction or molding pressure reduction, etc. are appropriately selected. It can also be adjusted by setting.

In particular, the resin foam of the present invention is obtained by impregnating a resin composition containing at least a nucleating agent and an aliphatic compound with a high-pressure gas (particularly an inert gas) in addition to a thermoplastic resin, It is preferably formed through a step of decompressing the product. As a result, it has a cell structure with a small average cell diameter, a low closed cell structure ratio, a high expansion ratio, good flexibility, and the cell structure is difficult to deform or compress, and strain recovery when pressed The resin foam having excellent properties and processability can be easily obtained.

The resin foam of the present invention is obtained by impregnating a supercritical inert gas with a resin composition containing at least a nucleating agent having a particularly small average particle diameter and an aliphatic compound in addition to a thermoplastic resin. It is more preferable that the resin composition is formed through a step of decompressing and stretching the obtained resin foam. As a result, the average cell diameter is extremely small, the cell structure has a low closed cell structure ratio, high foaming ratio, good flexibility, the cell structure is difficult to deform or compress, and distortion when pressed It is excellent in recoverability, can further suppress the nucleating agent from breaking through the cell wall, and furthermore, since the anisotropy is extremely high, it is possible to easily obtain a resin foam having better processability.

The resin foam of the present invention is a mixture of a thermoplastic resin and a rubber component and / or a thermoplastic elastomer component, the ratio of which is 70/30 to 30/70 on a weight basis, A resin composition containing at least 0.5 to 150 parts by weight of a nucleating agent with respect to 100 parts by weight of the thermoplastic resin and 1 to 5 parts by weight of an aliphatic compound with respect to 100 parts by weight of the thermoplastic resin, It is preferably formed through a step of depressurizing after impregnating with a high-pressure gas (particularly an inert gas).

[Foamed sealing material]
The foam sealing material of this invention is a member containing the said resin foam. Although the shape of a foaming sealing material is not specifically limited, A sheet form (a film form is included) is preferable. For example, the foamed sealing material may be configured only by a resin foam, or may be configured such that an adhesive layer, a base material layer, and the like are laminated on the resin foam.

In particular, the foamed sealing material of the present invention preferably has an adhesive layer. For example, when the foamed sealing material of the present invention is a sheet-like foamed sealing material, it may have an adhesive layer on one side or both sides. When the foamed sealing material has an adhesive layer, for example, a processing mount can be provided on the foamed sealing material via the adhesive layer, and further, it can be fixed or temporarily fixed to the adherend.

The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited. For example, acrylic pressure-sensitive adhesive, rubber-based pressure-sensitive adhesive (natural rubber-based pressure-sensitive adhesive, synthetic rubber-based pressure-sensitive adhesive, etc.), silicone-based pressure-sensitive adhesive, and polyester-based pressure-sensitive adhesive. In addition, known pressure-sensitive adhesives such as urethane pressure-sensitive adhesives, polyamide-based pressure-sensitive adhesives, epoxy-based pressure-sensitive adhesives, vinyl alkyl ether-based pressure-sensitive adhesives, and fluorine-based pressure-sensitive adhesives can be appropriately selected and used. An adhesive can be used individually or in combination of 2 or more types. The pressure-sensitive adhesive may be any type of pressure-sensitive adhesive such as an emulsion-based pressure-sensitive adhesive, a solvent-based pressure-sensitive adhesive, a hot-melt pressure-sensitive adhesive, an oligomer-based pressure-sensitive adhesive, and a solid-type pressure-sensitive adhesive. Among these, as the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive is preferable from the viewpoint of preventing contamination of the adherend.

The thickness of the adhesive layer is preferably 2 to 100 μm, more preferably 10 to 100 μm. The thinner the adhesive layer, the higher the effect of preventing the adhesion of dust and dirt at the end, and thus the thinner the adhesive layer, the better.
The pressure-sensitive adhesive layer may have any form of a single layer or a laminate, and may be foamable or non-foamable. Of these, a non-foaming pressure-sensitive adhesive layer is preferable.

In the foamed sealing material of the present invention, the pressure-sensitive adhesive layer may be provided via another layer (lower layer). Examples of such a lower layer include other pressure-sensitive adhesive layers, intermediate layers, undercoat layers, base material layers (particularly film layers, nonwoven fabric layers, etc.) and the like. The lower layer may be a foamable layer or a porous layer, but is preferably a non-foamable layer, more preferably a resin layer.
The adhesive layer may be protected by a release film (separator, for example, release paper, release film, etc.).

Since the foamed sealing material of the present invention contains the resin foam of the present invention, it has good dust resistance, particularly good dynamic dust resistance, and has flexibility to follow a minute clearance.

The foamed sealing material of the present invention may be processed so as to have a desired shape and thickness. For example, various shapes may be processed according to the device, equipment, casing, member, and the like used.

The foamed sealing material of the present invention is suitably used as a member used when various members or parts are attached (attached) to a predetermined site. In particular, the foamed sealing material of the present invention is suitable as a member used when attaching (attaching) a component constituting an electric or electronic device to a predetermined site in an electric or electronic device.

The various members or parts that can be attached or mounted using the foamed member are not particularly limited, and examples thereof include various members or parts in electrical or electronic devices. Examples of such a member or component for electric or electronic equipment include an image display member (display unit) (particularly a small image display member) mounted on an image display device such as a liquid crystal display, an electroluminescence display, or a plasma display. ), Optical members or optical components such as cameras and lenses (particularly small cameras and lenses) mounted on mobile communication devices such as so-called “mobile phones” and “portable information terminals”.

For example, the foamed sealing material of the present invention is preferably used around the display unit such as an LCD (liquid crystal display) and the display unit such as an LCD (liquid crystal display) and a housing for the purpose of dust prevention, light shielding, buffering, and the like. What is inserted and used between a body (window part) is mentioned.
When the foamed sealing material of the present invention is attached to such a member or part, it is preferably attached so as to close the clearance. The clearance is not particularly limited, and is, for example, 0.05 to 0.5 mm. Degree.
Hereinafter, the thermoplastic resin foam and foamed sealing material of the present invention will be described based on examples.

Example 1
As a resin composition,
35 parts by weight of polypropylene,
60 parts by weight of a thermoplastic elastomer composition,
5 parts by weight of lubricant,
Ten parts by weight of the nucleating agent and 2 parts by weight of erucic acid amide (melting point: 80 to 85 ° C.) were kneaded at a temperature of 200 ° C. with a twin-screw kneader.

Here, polypropylene is a resin having a melt flow rate (MFR) of 0.35 g / 10 min,
The thermoplastic elastomer composition contains 16.7% by weight of carbon black, and is a blend of polypropylene (PP) and ethylene / propylene / 5-ethylidene-2-norbornene terpolymer (EPT) (crosslinked olefin type). Thermoplastic elastomer, TPV), polypropylene: ethylene / propylene / 5-ethylidene-2-norbornene terpolymer = 10: 90 (weight basis),
The lubricant is a master batch in which 1 part by weight of stearic acid monoglyceride is blended with 10 parts by weight of polyethylene,
The nucleating agent is magnesium hydroxide having an average particle size of 0.8 μm.

Thereafter, the resin composition was extruded into strands, cooled with water, cut into pellets, and molded.
This pellet was put into a tandem type single screw extruder manufactured by Nippon Steel Works Co., Ltd., and 3.8% by weight of carbon dioxide gas was injected under an atmosphere of 220 ° C. under a pressure of 14 (18 after injection) MPa. Carbon dioxide gas was sufficiently saturated and cooled to a temperature suitable for foaming. After that, in order to extrude from the die and obtain an anisotropic structure, the ratio of the resin extrusion speed to the molding speed is adjusted to be within the range of 1: 1.2 to 1: 2, and the foam is slack in the line. The sheet-shaped resin foam was obtained by adjusting the thickness to 1 mm. This resin foam had a semi-continuous semi-closed cell structure with a tensile modulus of 9.3 MPa and a closed cell rate of 32%.

(Example 2)
A sheet-like resin foam was produced in substantially the same manner as in Example 1 except that the thickness was adjusted to 0.5 mm. This resin foam had a semi-continuous semi-closed cell structure with a closed cell rate of 32%. The extensibility at 0.5N was 3.7%, and the extensibility at 1.0N was 7.2%.

(Comparative Example 1)
Urethane foam (main component: polyurethane, sheet, average cell diameter: 229 μm, apparent density: 0.24 g / cm ³ ) was prepared as an isotropic foam.

(Measurement method of closed cell ratio)
The closed cell ratio of the resin foams obtained in Examples and Comparative Examples was measured according to the following method.
From the obtained resin foam, a flat square test piece having a constant thickness and a side of 5 cm is cut out. Subsequently, the weight W1 (g) and thickness (cm) of the test piece are measured, and the apparent volume V1 (cm ³ ) of the test piece is calculated.
Next, the obtained value is substituted into the formula (1), and the apparent volume V2 (cm ³ ) occupied by the bubbles is calculated. The density of the resin constituting the test piece is ρg / cm ³ .
Apparent volume occupied by bubbles V2 = V1−W1 / ρ (1)
Subsequently, the test piece is submerged in distilled water at 23 ° C. so that the distance from the upper surface of the test piece to the water surface is 40 mm and left for 24 hours. Then, a test piece is taken out from distilled water and the water | moisture content adhering to the surface of the test piece is removed. The weight W2 (g) of the obtained test piece is measured, and the open cell ratio F1 is calculated based on the formula (2). The closed cell rate F2 is obtained from the open cell rate F1.
Open cell ratio F1 = 100 × (W2−W1) / V2 (2)
Closed cell ratio F2 = 100−F1 (3)

(Tensile modulus)
The tensile test based on JISK6767 was implemented, and it calculated based on the following formula by the inclination under the elastic region in the obtained stress strain curve. That is, it was obtained by the ratio of the stress and the corresponding strain under the elastic region in the stress strain curve.
Tensile modulus (MPa) = stress / strain

(Extensible)
A. Extensibility (0.5N)
The resin foam was cut out in the MD direction to prepare a sheet-like test piece having a thickness of 0.5 mm, a width of 3 mm, and a length of 30 mm. With one end in the length direction of the test piece fixed, the test piece was stretched in the length direction with a load of 0.5 N, and the length of the test piece after stretching was measured. Based on the following formula, spreadability (%) was determined.
Spreadability (%) = 100 × [(length of test piece after stretching) − (length of initial test piece)] / (length of initial test piece)
If the stretchability (0.5N) is 5.0% or less, it is difficult to extend, and it can be determined that it is good.
B. Extensibility (1.0N)
Except for the load being 1.0 N, extensibility (%) was determined in the same manner as extensibility (0.5 N).
If the stretchability (1.0 N) is 10.0% or less, it is difficult to extend, and it can be determined that it is good.

(Evaluation)
The following evaluation was performed about the sheet | seat of the resin foam of an Example and a comparative example. The results are shown in Table 1.

(Apparent density measurement method)
Using the sample obtained by cutting the resin foam into 20 mm × 20 mm, the apparent density (g / cm ³ ) of the foam was calculated from the weight of the sample and the buoyancy with a density meter.

(Maximum breaking strength Smax and breaking strength Smin / breaking elongation SSmax and SSmin measurement method)
First, the breaking strength in an arbitrary direction (for example, direction A) of the resin foam is measured, and a center X is set on the axis in the direction A, and the axis is rotated by 10 ° with respect to the center X. The breaking strength in each direction indicated by each axis was measured (18 directions in total). Among them, the breaking strength in the direction with the largest breaking strength was selected, and this was set as the maximum breaking strength Smax.
In the resin foam of the example, the direction showing the maximum breaking strength Smax coincided with the MD direction. Therefore, the direction orthogonal to the direction showing the maximum breaking strength coincides with the TD direction.
For the breaking strength, a resin foam was punched into dumbbell No. 1, a tensile test was performed at a distance between chucks of 50 mm and a pulling speed of 500 mm / min, the strength and elongation at the breaking point were measured, and an average value of five points was calculated. , The breaking strength and elongation at break, respectively.

(Measurement method of bubble size)
Cut the resin foam in a direction perpendicular to the main surface of the resin foam (thickness direction) in parallel with the maximum breaking strength direction, which will be described later, and the direction perpendicular to this direction, and create a smooth cross section. did.
These cross sections were taken into a Keyence microscope (for example, trade name “VHX-600” manufactured by Keyence Corporation), and image analysis was performed using the analysis software (Mitani Corporation, Win ROOF) of the same instrument. Within the measurement range of resin foam 3000μm × 2500μm, measure the diameter from the pixel area of the image as the bubble diameter, extract 10 points from those with a large bubble diameter, find the average, and calculate the bubble size It was.

(Hand cutting)
As shown in FIG. 1, a sample 1 having a width of 40 mm and a length of 100 mm was produced, and a cut 1a was cut into the sample 1 up to 50 mm at a position of a width of 20 mm in parallel with the longitudinal direction. As shown in FIG. 2, after fixing the sample 1 to the grip 2 of the tensile tester, the sample 1 was pulled in the Z direction at a tensile speed of 500 mm / min until the sample 1 was broken and separated. The sharpness was judged visually. When the position shift (Q in FIG. 1) from the cut position to the broken end was within 5 mm (20%), the hand cutting performance was evaluated as good.

According to Table 1, the resin foams of Examples 1 and 2 have a large value of Smax / Smin and have significant anisotropy in shear fracture in a specific direction, and therefore, good workability can be realized. confirmed.

The present invention is useful as a heat insulating material, food packaging material, clothing material, building material, internal insulator such as electronic equipment, cushioning material, sound insulating material, dustproof material, shock absorbing material, light shielding material, etc., flexibility, cushioning property, etc. In addition, it is a resin foam and a foam sealing material that have excellent workability and a high expansion ratio, and can be widely used for various members.

DESCRIPTION OF SYMBOLS 1 Sample 2 Gripping part 10 T die or slit die 11 Resin sheet 12 Nip roll 20 Resin foam 21 Roller

Claims

A resin foam containing a thermoplastic resin,
The foam has a maximum breaking strength Smax of 0.1 MPa to 3 MPa, and a ratio Smax / Smin between the maximum breaking strength Smax and a breaking strength Smin in a direction perpendicular to the direction showing the maximum breaking strength is 1.5 to 6 The resin foam characterized by being.
The elongation at break SSmax in the direction showing the maximum breaking strength is 200% or less,
The resin foam according to claim 1, wherein a breaking elongation ratio SSmax / SSmin between a breaking elongation SSmax in the direction showing the maximum breaking strength and a breaking elongation SSmin in a direction perpendicular to the direction showing the maximum breaking strength is 1.5 to 6. body.
The resin foam according to claim 1 or 2, wherein a ratio Cmax / Cmin between the bubble size Cmax in the direction showing the maximum breaking strength and the bubble size Cmin in the direction orthogonal to the direction showing the maximum breaking strength is 1.2 to 5. body.
The resin foam according to any one of claims 1 to 3, wherein an apparent density is 0.01 to 0.2 g / cm 3 .
The thermoplastic resin foam according to any one of claims 1 to 4, obtained by decompression treatment of a thermoplastic resin composition impregnated with a high-pressure gas.
The resin foam according to claim 5, wherein the gas is an inert gas.
The resin foam according to claim 6, wherein the inert gas is carbon dioxide or nitrogen.
The resin foam according to any one of claims 5 to 7, wherein the gas is a gas in a supercritical state.
A foamed sealing material comprising the resin foam according to any one of claims 1 to 8.
The foaming sealing material of Claim 9 provided with the adhesion layer arrange | positioned at the single side | surface or both surfaces of a foam.
The foamed sealing material according to claim 10, wherein the adhesive layer is disposed on the surface of the resin foam via a film layer.